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Texacephale Referred Specimen By Nick Longrich
''Texacephale'' is a pachycephalosaurid dinosaur from the Campanian stage of the Late Cretaceous. Its fossils come from the Aguja Formation of Big Bend National Park, in Texas, and were described in 2010 by Longrich, Sankey and Tanke. The generic name means Texas + "head" (''kephale'' in Greek) in reference to its place of discovery, and the specific name honors Wann Langston. Discovery The holotype specimen of ''Texacephale'', LSUMNS 20010, is composed of fused frontals and parietals. A second specimen, LSUMNS 20012, is composed of an incomplete frontoparietal dome. It was found in the same WPA quarries that produced '' Agujaceratops'', and may have been excavated and tossed aside, being mistaken for a rock or concretion, before being picked up decades later. According to the team, the fossilized dome of the animal possessed five to six vertical flanges on each lateral side, connecting it with the postorbital bone. The team interpreted these structures as interlocking "ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Campanian
The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian spans the time from 83.6 (± 0.2) to 72.1 (± 0.2) million years ago. It is preceded by the Santonian and it is followed by the Maastrichtian. The Campanian was an age when a worldwide sea level rise covered many coastal areas. The morphology of some of these areas has been preserved: it is an unconformity beneath a cover of marine sedimentary rocks. Etymology The Campanian was introduced in scientific literature by Henri Coquand in 1857. It is named after the French village of Champagne in the department of Charente-Maritime. The original type locality was a series of outcrop near the village of Aubeterre-sur-Dronne in the same region. Definition The base of the Campanian Stage is defined as a place in the stratigraphic col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parietal Bone
The parietal bones () are two bones in the skull which, when joined at a fibrous joint, form the sides and roof of the cranium. In humans, each bone is roughly quadrilateral in form, and has two surfaces, four borders, and four angles. It is named from the Latin ''paries'' (''-ietis''), wall. Surfaces External The external surface ig. 1is convex, smooth, and marked near the center by an eminence, the parietal eminence (''tuber parietale''), which indicates the point where ossification commenced. Crossing the middle of the bone in an arched direction are two curved lines, the superior and inferior temporal lines; the former gives attachment to the temporal fascia, and the latter indicates the upper limit of the muscular origin of the temporal muscle. Above these lines the bone is covered by a tough layer of fibrous tissue – the epicranial aponeurosis; below them it forms part of the temporal fossa, and affords attachment to the temporal muscle. At the back part and clos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hanssuesia
''Hanssuesia'' is a genus of pachycephalosaurid dinosaurs from the late Cretaceous period. It lived in what is now Alberta and Montana, and contains the single species ''Hanssuesia sternbergi''. ''Hanssuesia'' is based on a skull dome originally named ''Troodon sternbergi'' by Barnum Brown and Erich Maren Schlaikjer in 1943. The specific name honoured Charles Mortram Sternberg who found the dome in 1928 near Steveville in south Alberta. In 1945, it was transferred to ''Stegoceras'' by C.M. Sternberg himself, as a ''Stegoceras sternbergi''. The genus ''Hanssuesia'' was first named by Robert M. Sullivan in 2003. It honours paleontologist Hans-Dieter Sues. In the publication also the spelling variant "Hanssuessia" appeared; the same year Sullivan chose for ''Hanssuesia'' as the valid name. Its type species is ''Troodon sternbergi'', the ''combinatio nova'' is ''Hanssuesia sternbergi''. ''H. sternbergi'' is known from the holotype NMC 8817 and six referred specimens (mainly fronto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colepiocephale
''Colepiocephale'' (meaning "knucklehead") is a genus of pachycephalosaurid dinosaur from Late Cretaceous (middle Campanian stage) deposits of Alberta, Canada. It was collected from the Foremost Formation (middle Campanian, 80–77.5 ma). The type species, ''C. lambei'', was originally described by Sternberg (in 1945 as ''Stegoceras lambei''C. M. Sternberg. 1945. Pachycephalosauridae proposed for dome-headed dinosaurs, Stegoceras lambei, n. sp., described. Journal of Paleontology 19(5):534-538), and later renamed by Sullivan in 2003. ''C. lambei'' is a domed pachycephalosaur characterized principally by the lack of a lateral and posteriosquamosal shelf, a steeply down-turned parietal, and the presence of two incipient nodes tucked under the posterior margin of the parietosquamosal border. See also * Timeline of pachycephalosaur research This timeline of pachycephalosaur research is a chronological listing of events in the history of paleontology focused on the pachycephalo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravitholus
''Gravitholus'' (meaning 'heavy dome') was a genus of pachycephalosaurid dinosaur from the late Cretaceous period (Campanian stage, around 75 million years ago). It was a pachycephalosaur, and like other pachycephalosaurids the skull roof formed a thick dome made of dense bone, which may have been used in head-butting contests over mates or territory. It lived in what is now Alberta, Canada, and was described in 1979 by W. P. Wall and Peter Galton. The type species is ''Gravitholus albertae''. There is some debate amongst paleontologists as to whether the animal represents a distinct genus, or if it may be synonymous with ''Stegoceras''. Recent publications indicate it may be a valid genus. ''Gravitholus'' is one of several pachycephalosaurids known from Dinosaur Park, including '' Stegoceras validum'', '' Hanssuesia sternbergi'', and '' Foraminacephale brevis''. It is unclear whether all of these species would have lived in the area at the same time. A 2020 CSVP abstract found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stegoceras
''Stegoceras'' is a genus of pachycephalosaurid (dome-headed) dinosaur that lived in what is now North America during the Late Cretaceous period, about 77.5 to 74 million years ago (mya). The first specimens from Alberta, Canada, were described in 1902, and the type species ''Stegoceras validum'' was based on these remains. The generic name means "horn roof", and the specific name means "strong". Several other species have been placed in the genus over the years, but these have since been moved to other genera or deemed junior synonyms. Currently only ''S. validum'' and ''S. novomexicanum'', named in 2011 from fossils found in New Mexico, remain. The validity of the latter species has also been debated. ''Stegoceras'' was a small, bipedal dinosaur about long, and weighed around . The skull was roughly triangular with a short snout, and had a thick, broad, and relatively smooth dome on the top. The back of the skull had a thick "shelf" over the occiput, and it had a thick rid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to descendants, nor does it show how much they have changed, so many differing evolutionary trees can be consistent with the same cladogram. A cladogram uses lines that branch off in different directions ending at a clade, a group of organisms with a last common ancestor. There are many shapes of cladograms but they all have lines that branch off from other lines. The lines can be traced back to where they branch off. These branching off points represent a hypothetical ancestor (not an actual entity) which can be inferred to exhibit the traits shared among the terminal taxa above it. This hypothetical ancestor might then provide clues about the order of evolution of various features, adaptation, and other evolutionary narratives about an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deinosuchus
''Deinosuchus'' () is an extinct genus of alligatoroid crocodilian, related to modern alligators and caimans, that lived 82 to 73 million years ago (Ma), during the late Cretaceous period. The name translates as "terrible crocodile" and is derived from the Greek ''deinos'' (δεινός), "terrible", and ''soukhos'' (σοῦχος), "crocodile". The first remains were discovered in North Carolina (United States) in the 1850s; the genus was named and described in 1909. Additional fragments were discovered in the 1940s and were later incorporated into an influential, though inaccurate, skull reconstruction at the American Museum of Natural History. Knowledge of ''Deinosuchus'' remains incomplete, but better cranial material found in recent years has expanded scientific understanding of this massive predator. Although ''Deinosuchus'' was far larger than any modern crocodile or alligator, with the largest adults measuring in total length, its overall appearance was fairly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratopsidae
Ceratopsidae (sometimes spelled Ceratopidae) is a family of ceratopsian dinosaurs including ''Triceratops'', ''Centrosaurus'', and ''Styracosaurus''. All known species were quadrupedal herbivores from the Upper Cretaceous. All but one species are known from western North America, which formed the island continent of Laramidia during most of the Late Cretaceous. Ceratopsids are characterized by beaks, rows of shearing teeth in the back of the jaw, elaborate nasal horns, and a thin parietal-squamosal shelf that extends back and up into a frill. The group is divided into two subfamilies— Chasmosaurinae and Centrosaurinae. The chasmosaurines are generally characterized by long, triangular frills and well-developed brow horns. The centrosaurines had well-developed nasal horns or nasal bosses, shorter and more rectangular frills, and elaborate spines on the back of the frill. These horns and frills show remarkable variation and are the principal means by which the various species have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agujaceratops Mariscalensis
''Agujaceratops'' (meaning "horned face from Aguja") is a genus of horned dinosaur from the Late Cretaceous (Campanian) of west Texas. It is a chasmosaurine (long-frilled) ceratopsian. Two species are known, ''Agujaceratops mariscalensis'', and ''A''. ''mavericus''. Discovery and species In 1938, three dinosaur bone beds were excavated, and ceratopsian material was collected from Big Bend National Park (Texas) by William Strain. This material was studied by Lehman in 1989 and named ''Chasmosaurus mariscalensis''. It is known only from the holotype UTEP P.37.7.086 a partial adult skull which includes a braincase, left supraorbital horncore, left maxilla and a right dentary. Additional material was associated with the holotype, but not considered to be part of it. All specimens of ''Agujaceratops'' were collected from the lower part of the Upper Shale member of the Aguja Formation, dating to about 77 million years ago, in the Big Bend National Park, Brewster County. Addition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Interior Seaway
The Western Interior Seaway (also called the Cretaceous Seaway, the Niobraran Sea, the North American Inland Sea, and the Western Interior Sea) was a large inland sea that split the continent of North America into two landmasses. The ancient sea, which existed from the early Late Cretaceous (100 million years ago) to the earliest Paleocene (66 Ma), connected the Gulf of Mexico, through the United States and Canada, to the Arctic Ocean. The two land masses it created were Laramidia to the west and Appalachia to the east. At its largest extent, it was deep, wide and over long. Origin and geology By Late-Cretaceous times, Eurasia and the Americas had separated along the south Atlantic, and subduction on the west coast of the Americas had commenced, resulting in the Laramide orogeny, the early phase of growth of the modern Rocky Mountains. The Western Interior Seaway may be seen as a downwarping of the continental crust ahead of the growing Laramide/Rockies mountain chain. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
